The 16-year wait came to an end without the Yorkshire club even kicking a ball as Albion needed to beat Huddersfield to prolong Marcelo Bielsa's side's wait for promotion.
But following West Brom's defeat to Huddersfield thanks to goals from Chris Willock and Emile Smith Rowe, Leeds' place back in the Premier League has been sealed.
The result at the John Smith's Stadium meant Championship leaders Leeds secured a top-two finish with 87 points - five points ahead of West Brom who have played one game more.
Leeds, who beat Barnsley 1-0 on Thursday, will play in England's highest division for the first time since 2004.
Since then Leeds have also spent three years in League One between 2007 and 2010, but have finally ended their top-flight wait after several near misses.
They missed out on promotion last season in the playoffs despite looking favourites for automatic promotion for much of the campaign.
Leeds, who visit Derby County on Sunday, can also seal the title without kicking a ball if third-placed Brentford fail to win at Stoke City on Saturday.
Leeds fan celebrate outside Elland Road after they secure promotion to the Premier League
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Leeds' long road back
Three times English champions, Leeds were relegated from the Premier League in 2004 after hitting financial trouble and being forced to sell a host of big-name players such as Robbie Keane, Jonathan Woodgate and Lee Bowyer.
The problems were only just starting though and after three years in the Championship they slipped to the third tier and into administration with the future of the club in doubt.
While they eventually regained their place in the Championship in 2010 they never really challenged for promotion until the enigmatic Bielsa took charge in 2018.
They have been transformed under the former Argentina coach and can now look forward to renewing old rivalries with the likes of Manchester United and Liverpool.
Leeds United players at a window inside Elland Road gesture to supporters gathering outside
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